Oh physicists, you’re always injecting so much personality into the way we think about the world. Today brought the discovery that when a physicist talks about reluctance, they mean the magnetic version of electrical resistance. A magnetic resistor, so to speak.
So, something with high reluctance blocks the flow of magnetic flux, and causes a ‘magneto-motive force drop’ across the region. The whole construction lets you pretend that magnetic fields and magnetism act just like electric fields and so you can use electronics laws to figure out whacky things like “magnetic circuits”.
I’m still getting a handle on the differences between magnetic “permeance”, “permitivity”, and “permeability” (and I’m grateful for any insight) — on the other hand, I now know that “coercivity” (imagine that) is the ease with which a material can be demagnetized. Neodymium magnets have an especially high coercivity — it’s hard to [coerce them to] demagnetize.